EASA AD No.: 2011-0148

EASA Form 110 Page 1/3 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2011-0148

Date: 05 August 2011

Note: This Airworthiness Directive (AD) is issued b y EASA, acting in accordance with Regulation (EC) No 216/2008 on behalf of the Europe an Community, its Member States and of the European third countries that participate in the activities of EASA under Article 66 of that Regulation.
This AD is issued in accordance with EC 1702/2003, Part 21A.3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, the continuing airworthiness of an aircraft shall be en sured by accomplishing any applicable ADs. Conseque ntly, no person may operate an aircraft to which an AD applies, except in accor dance with the requirements of that AD, unless othe rwise specified by the Agency [EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 216/200 8, Article 14(4) exemption].


### Type Approval Holder’s Name : Eurocopter Deutschland GmbH Type/Model designation(s) : MBB-BK117 helicopters

TCDS Number : EASA.R.010

Foreign AD : Not applicable

Supersedure : This AD supersedes EASA AD 2011-0131 dated 08 July 2011.



### ATA 85 Optional Equipment – External Rescue Hoist System – Deactivation / Modification

Manufacturer(s): Eurocopter Deutschland GmbH (ECD), Eurocopter Hubschrauber GmbH, Messerschmitt-Bölkow-Blohm GmbH
Applicability: MBB-BK117 

### A-1, MBB-BK117 

### A-3, MBB-BK117 

### B-1, MBB-BK117 

### B-2 and MBB-BK117 

### C-1 helicopters, all serial numbers.

Reason: In a recent incident with a MBB-BK117 C-1 h elicopter, the cable cut-off function of the rescue hoist was triggered uncomman ded and the hoist cable was cut. The subsequent investigation revealed that this was caused by a malfunction within the remote control handle assemb ly of the rescue hoist system, when extending the hoist boom. This condition, if not detected and corrected, woul d lead to detachment of an external load or person from the helicopter hoist, possibly resulting in personal injury, or injury to persons on the ground

. The same Part Number (P/N) 117-80403 and P/N 117-80 4061 hoist systems are known to be installed on other models of the sa me type design. To address this potential unsafe condition, EASA is sued AD 2011-0126 to require deactivation of the affected external hoist system by pulling and securing the related circuit breakers, or by removi ng the hoist boom. Pending the results of the investigation, EASA AD 2011-0126 also prohibited installation of an affected external hoist system o n any other helicopter. Following issuance of EASA AD 2011-0126, it was dis covered that by pulling the circuit breaker WARN ANN II, the redundant powe r supply of theEASA AD No.: 2011-0148

EASA Form 110 Page 2/3 Annunciator System is degraded which in case of sec ond helicopter system failure could be not annunciated to pilots. Prompte d by these findings, EASA issued EASA AD 2011-0131, which superseded EASA AD 2011-0126, retained partially its requirements and required pu lling only three (3) circuit breakers (CABLE CUTTER, WINCH CONT. and WINCH BOOM) while the circuit breaker for WARN ANN II must remain inserte d. Since EASA AD 2011-0131 was issued, a corrective ac tion has been developed to establish an adequate safety level, wh ile a terminating action is under investigation but currently not available. For the reasons described above, this AD retains th e requirements of EASA AD 2011-0131, which is superseded, and requires rep etitive inspections of the external hoist system control handle with coile d cable, Part Number (P/N) 76803, modification of helicopter wiring and a revi sion of the related Flight Manual Supplement. This AD also requires implementa tion of a 10-year time between overhaul (TBO) for the external hoist syste m control handle with coiled cable. This AD is still considered to be an interim measure and further AD action may follow.

Effective Date: 12 August 2011

Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previous ly: Re-statement of requirements of EASA AD 2011-0131: (1) For helicopters equipped with (optional) rescue hoist (sometimes referred to as rescue winch), P/N 117-80403 or P/N 117-804061, accomplish one of the actions, paragraph (1.1) or ( 1.2) below: (1.1) Before the next hoist operation, or within 30 days, whichever occurs first after 12 July 2011 [the effective date of AD 2011-0131], deactivate the external hoist system by pulling the three (3) affected circuit breakers, CABLE CUTTER, WINCH CONT . and WINCH BOOM, and securing each with a cable tie, or (1.2) Before the next hoist operation, or within 30 days, whichever occurs first after from 05 July 2011 [the effective date of EASA AD 2011-0126], remove the hoist boom in accordance wit h the instructions of Chapter 832 of the applicable ECD M BB-BK 117 Maintenance Manual. (2) For all other helicopters, from 05 July 2011 [t he effective date of EASA AD 2011-0126], do not install an affected P/N rescu e hoist, as identified in paragraph (1) of this AD, on any helicopter, unl ess the installation is in compliance with the requirements of paragraph (1) o r in compliance with the requirements of paragraph (3) of this AD. New requirements of this AD: (3) For helicopters equipped with (optional) rescue hoist, P/N 117-80403 or P/N 117-804061, before the next hoist operation, or within 30 days, whichever occurs first after the effective date of this AD, accomplish the following actions concurrently: (3.1) Modify the helicopter wiring and the operator handle P/N 76803 to deactivate the external hoist system cable cutter f unction in accordance with the instructions of ECD Alert Servi ce Bulletin (ASB) MBB-BK117-80-166 Revision 1 (Rev.1), and (3.2) Replace the affected pages of the relevant Ro torcraft Flight Manual (RFM) and its applicable Supplement (RFMS) w ith the applicable Temporary Revision (TR) as listed in Tab le 1 of this AD, to incorporate pre-flight check instructions for th e condition of the control handle P/N 76803, including the coiled cabl e.EASA AD No.: 2011-0148

EASA Form 110 Page 3/3 Table 1

RFM TR No.
BK117 C1C 2
BK117 C1 3
BK117 B2 S/N7203 2
BK117 B2 2
BK117 B1 7
BK117 A4 6
BK117 A3 10

(4) Concurrent with the modification as required by paragraph (3) of this AD, and thereafter at intervals not to exceed 30 da ys (+ 10% tolerance), inspect the control handle P/N 76803 for damage, in accordance with the instructions of ECD ASB MBB-BK117-80-166 Rev.1. (5) If, during any pre-flight check as required by paragraph (3) of this AD, or during any inspection as required by paragraph (4) of this AD, damage is detected, before the next hoist operation, repla ce the control handle P/N 76803 with a serviceable part. (6) From the effective date of this AD, do not inst all a control handle P/N 76803 on any helicopter, unless it has been modifie d in accordance with the instructions of ECD ASB MBB-BK117-80-166 Rev.1. (7) Modification of a helicopter as required by par agraph (3) of this AD cancels the requirements of paragraph (1) of this A D for that helicopter. (8) Within 10 years after first installation on a h elicopter, or within 9 months after the effective date of this AD, whichever occu rs later, and thereafter at intervals not to exceed 10 years, accomplish an overhaul of the control handle P/N 76803.

Ref. Publications: ECD ASB MBB-BK117-80-166 Revision 1 dated 04 August 2011. The use of later approved revisions of this documen t is acceptable for compliance with the requirements of this AD.

Remarks : 1. If requested and appropriately substantiated, EA SA can approve Alternative Methods of Compliance for this AD. 2. The required actions and the risk allowance have granted the issuance of a Final AD with Request for Comments, postponing the public consultation process after publication. 3. Enquiries regarding this AD should be referred t o the Safety Information Section, Executive Directorate, EASA. E-mail ADs@easa.europa.eu 4. For any question concerning the technical conten t of the requirements in this AD, please contact: Eurocopter Deutschland GmbH, Industriestrasse 4, 86607 Donauwörth, Federal Republic of Germany Telephone: + 49 (0)151-1422 8976; Facsimile: + 49 ( 0)906-71 4111.